This invention relates to hardware for the closure of a window or door, which closure is at least lockable in spaced, parallel position and in this position is horizontally shiftable. The hardware has lower and upper swing arms which are pivotally mounted, on the one hand, on the lower transverse closure bar and, on the other hand, on a traveling carriage. A releasable locking device is provided at least for the lower swing arms when they are located in the parallel-stop position. The locking device consists of a supporting lever operating on the swing arm in the region of the traveling carriage and can be brought into operative engagement with an abutment located on the stationary frame during the slide-to-close motion of the closure.
Hardware of this kind has already been disclosed in U.S. Pat. No. 2,741,807 and also in French Pat. No. 1,551,381. Their advantage resides in the fact that, with a simple design construction, they are robust in use and can, therefore, also be used when heavy closures are to be brought out into a parallel-stop position relative to the stationary frame and then to be shifted horizontally.
The construction principles of these known hardware designs are such that the supporting lever in each case has to interact over the total length of the horizontal shifting path of the closure with a stationary abutment when the parallel-stop position of the swing arms is to be fixed in any possible slide position.
In the hardware as shown in the U.S. Pat. No. 2,741,807, the supporting lever can also be released in an undesirable manner on account of its swivel mounting provided at the closure and because of objects projecting into the path of motion of its control lug, before it has attained its shift-close end position. This deficiency has been avoided on the hardware shown in the French Pat. No. 1,551,381; in that case, the supporting lever is mounted at the traveling carriage and its control lug is constantly in guiding contact till the closure has reached the shift-close end position. Only then the control lug (and thereby the supporting lever for the swing arms) is rendered free, so that the closure can subsequently be moved by means of the swing arms into its closed position in the stationary frame.
In the case of the hardware shown in the German Pat. OS No. 32 34 677, the locking device which determines the parallel stop position of the swing arms can be pressed undesirably out of the locking position by means of objects getting into the path of motion of a lock element located on a control arm.
Unlike the hardware shown in the U.S. Pat. No. 2,741,807, in the case of a similar fitting shown in German GM No. 84 35 367, a supporting lever designed as a bell crank is pivotally mounted on the traveling carriage. The supporting lever is so designed that a control lug provided on one of its lever arms always leads the traveling carriage in the shift-close position, while the lever arm facing the swing arm is more or less oriented at an obtuse angle position relative to the traveling carriage in the shift-close direction of the closure.
In the case of the hardware shown in U.S. Pat. No. 2,741,807 and German Pat. OS No. 32 34 677, the supporting lever fixing the parallel-stop position of the swing arms can be undesirably pressed out from its locking position before arriving at the stationary thrust abutment, because of objects getting into the path of motion of its control lug, since the control lug seen in shift-close position of the closure is constantly exposed ahead of the traveling carriage.
It is, therefore, an object of the present invention to provide hardware of the initially-described kind in which the swing arms are securely fixed in their parallel-stop position by means of a releasable locking device and in which a cam abutment working in cooperation with the control lug of the supporting lever is provided at the stationary frame only in the region of the shift-close motion of the closure.
With these and other objects in view, as will be apparent to those skilled in the art, the invention resides in the combination of part set forth in the specification add covered by the claims appended hereto.